Method and machine for closing bags



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3m'aentor Jan. 26, 1932. 1. w'. LITCHFIELD METHOD AND MACHINE FOR CLOS ING BAGS "r Sheets-Sheet 4 Filed April 29. 1929 I u EE 3.8 /4 r ak uv (Ittomegs L w. LITCHFIELD 1,842,680

METHOD AND MACHINE FOR CLOSING BAGS 7 Sheets-Sheet 5 Filed April 29, 1929 Zsnuentor 00M Gttomeg Jan. 26, 1932.

H. W. LITCH FIELD METHOD AND MACHINE FOR CLOSING BAGS Filed April 29, 1929 'T Sheets-Sheet 6' Jan. 26, 1932. 1. w. LITCHFHELD 1,842,680

METHOD AND MACHINE FOR CLOSING BAGS Filed April 29, 1929 7 Sheets-Sheet 7 Gttornega tight, and

ll atented dart 2th, llhdfi raur OFFICE ISAAC "W. LITCHFIELD, 0E BOSTON, MASSACHUSETTS, ASSIGNQR, BY MESNE ASSIGN- MENTS, TO SARAIN'AC BAG SEALERS, INU,

IPURATION 013 DELAWARE 0F BENTON HARBOR, MICHIGAN, A COR- IVIETHOD AND MACHINE FOR CLOSING BAGS Application filed April as,

This invention relates to a method and machine for closing flexible containers of any suitable material and construction, such containers hereinafter being designated bags for convenience.

lt is an object of this invention to provide a novel method of closing bags whereby a strong, tight closure may be rapidly efiected by a continuously progressive procedure, as. distinguished from the heretofore known methods of closing bags wherein folding operations are effected at one or more stations and each ba is then moved bodil to successive stations wherein fastening means are inserted in the folds, as well as my prior method of closing bags by effecting the folding operations and inserting all of the fastening means into the folds at one station, as disclosed and claimed in Letters Patent No. 1,653,051 granted December 20, 1927,

ltnother object of this invention is to provide a method and machine for closing bags whereby a strong, tight closure may be rapidly elfected in relatively large bags, and in bags of relatively stiff material, and at either one or both ends thereof.

llnother object of this invention is to pro vide a method and machine for closing bags whereby the closure will be substantially air of a character that will prevent sifting of finely pulverized material, and one that will satisfy the requirements as to containers for poisonous materials and the like. Jlnother object of this invention is to proride a method and machine for closing bags whereby the resulting closure is of such strength as to minimize the likelihood of the bag being broken open at the closure by the u'eigl'it of the contained material or the rough handling to which such bags are frerpientl v subjected.

A iother object of this invention is to proa machine for closing bags which may it tt-ed h' 'h speed and effect a strong are of e bag 1 nottr objectof this invention is to pro a n iine for closing bags vliich is ca o of handling relatively large bags and it relatively stiff material. .i'hcr objc of this invention is to pro- 1929. Serial No. 359,060.

vide a machine for closing bags which is caautomatic feeding mechanism, all of the folding and fastening operations are automatically effected in proper sequence, and the bag is delivered from the machine in completed form without the intervention of an operator.

Another object of this invention is to provide a machine for closing bags which irons and compacts the closure so as to render the same substantially airtight.

Another object of this invention is to provide a machine for closing bags which assures a substantially even fold throughout the Width of the bag.

Another object of this invention is to provide a machine for closing bags in which the fastening means are applied to the folds of the closure in such close relationship that there is no danger of the contained material sifting through the closure Another object of the invention is to pro vide a machine for closing bags which performs like closing operations on the opposite ends of the bag blank.

Another object of this invention is to provide a machine for closing bags in which the completed closure is of such strong and rugged construction that there is little like Another object of this invention is to provide a machine for closing bags having mechanism for applying fastening means which is operative when, and only when a bag has passed through the folding mechanism and is in proper position for receiving the fastening means.

Another object of this invention is to provide a machine for closing bags which is rela tively simple and yet strong and rugged in construction.

Other objects of this invention are to pro vide a machine for closing bags having improved folding mechanism; also such a machine having improved means for controlling the operation of the fastening mechanism; also such a machine having improved feeding means; also such a machine having improved means for connecting a continuously rotating driving element with intermittently operating fastening mechanism.

Still other objects of the invention will appear as the description of the invention proceeds.

Stated generally, the method includes the steps of progressively subjecting a bag blank to a series of elements which continuously and progressively fold the material by gradual increments into a reverse fold of substantially T shape and then fold the arms of the T into reenforcing relationship with the stem of the T while ironing and compacing the component parts of the fold, so as to compress the material into an airtight closure, and as a continuation of thefolding operations, intermittently feeding the completed fold past a plurality of fastening mechanisms which insert a plurality of fastening elements simultaneously and in spaced relation at each stepped advance of the fold.

A machine by which this method may be performed and embodying the mechanical features of the present invention is illustrated in the drawings and hereinafter described in detail. for illustration is a machine adapted to simultaneously effect identical closures at the opposite extremities of a bag blank on the order of 27" long by 19" wide and made of five plies of fairly heavy brown paper so that there are ten thicknesses of material to be folded at each extremity. It is to be expressly understood, however, that the invention is not restricted to the practice of method in such a machine as described and illustrated, nor to a machine of the size and form described and illustrated. The mechanical features of the invention may be embodied in machines for handling smaller or larger bags, and in machines for handling lighter or heavier bag material. The invention may also be employed to effect a closure at one extremity only of the bag, and in the latter case the invention may be employed for closing filled bags by turning the mechanism through 90. The invention may also be embodied in machinesfor closing bag blanks, at one or both extremities, wherein the blank passes through the machine in a vertical or inclined plane, instead of in a horizontal The embodiment selected plane as illustrated, by turning the mechanism through the proper angle.

It is therefore to be expressly understood that the machine illustrated on the draw ings has been selected for purposes of exemplification only, as the method herein described can be carried out in other machines, while the mechanical featuresof the invention are capable of receiving a variety of mechanical expressions, so that reference is to be had to the appended claims for a definition of the limits of the invention.

Referring in detail to the drawings, wherein the same reference characters are employed to designate corresponding parts in the several figures;

Fig. 1 is a side elevation of a machine embodying the present invention;

Fig. 2 is a longitudinal cross section through the machine, looking toward the side of the machine seen in Fig. 1;

Fig. 2a is a diagrammatic view illustrating the action of the successive rotary folding mechanisms on the bag material as effected by the several rotary folding elements vertically below them in Fig. 2;

Fig. 3 is a perspective view of the first six rotary folding stages and of the driving mechanism therefor;

Fig. 4 is a perspective view of one of the pairs of folding 0r tucking plates such as are disposed between the succeeding sets of rotary folders;

Fig. 5 is a transverse section taken through the axis of one of the rotary folders, i. e. the rolls of the sixth rotary folding stage as shown by section line 5-5 of Fig. 2;

Fig. 6 is a perspective view of the mechanism effecting the seventh to the tenth stages of rotary folding operations;

Fig. 7 is a fra mentary elevation showing the last stage 0 the rotary folding operations and the mechanism for bringing the fastening mechanism into operation;

Fig. 8 is a perspective view of elements shown in Fig. 7

Fig. 9 is a perspective view of the bag feeding mechanism and the driving elements therefor and of the mechanism for bringing the fastening mechanism into operation;

Fig. 10 is a perspective view of the automatic clutch mechanism;

Fig. 11 is an axial section on the line 1111 of Fig. 10 of the automatic clutch mechanism;

Fig. 12 is a fragmentary view of a detail of the automatic clutch mechanism;

Fig. 13 is a fragmentary view of the foldengaging guides adjacent the fastening mech anism; and

Fig. 14 is a perspective diagrammatic view of the completed bag, and also illustrates the bag engaging elements of the feeding mechanism in the position which they occupy during the operation of the fastening mechanism.

A machine embodying the mechanical features of the present invention may be pro- 5 vided with a frame of any suitable size, con struction and material. As illustrated, the frame is composed of rigid longitudinal elements 1 connected at or adjacent their extremities and at suitable intermediate points 10 by transverse members 2, so as to form a horizontally disposed generally rectangular open framework, which may be carried by a suitable number of legs on uprights 3 projecting from a base or foundation 4, or the legs 3 may rest directly upon the floor. Where, as illustrated, closures are to be effected at both extremities of the bag blank, the longitudinal members 1 are spaced apart by a distance somewhat greater than the length of the bag blank to be acted upon.

Projecting from or formed at one end of the frame is a suitable platform 6 upon which the bag blank is placed to enter the machine. The blanks may be fed to the table 6 by hand, or by any suitable feeding mechanism. To support the body of the blank during its progress through the folding and fastening mechanisms, longitudinally extending wires or rods 7 and 7 are suitably mounted on transverse members 2, at appropriate distances transversely of the frame, as shown at 8 in Figs. 3 and 9. If desired the blank receiving platform 6 may be formed by ex tensions of the rods or wires 7, or the plat form may be separately formed, as shown. If preferred a solid platform may replace the wires or rods 7.

. In accordance with the method of the present invention, the bag blank, illustrated as a straight line at 9 in Fig. 2a, is to be continuously and progressively subjected to a plurality of folding elements which will successivey score and bend by gradual increments the material of the bag, first into the form of a reentrant fold of T shape, and then fold the arms of the T into reenforcing relationship with the stem thereof. These folding elements are preferably arranged relatively close together so that a plurality of the fold 0 ing elements are operating on the blank at one time.

Any suitable number of folding stages may be employed in accordance with the present invention, the number of stages through which the blank is passed in effecting the completed fold varying with the character and stiffness of the material being operated upon. In the form shown, the blank is passed through eleven rotary folding stages, and in between each two successive stages the fold is also preferably subjected to the action of stationary folding or tucking plates which not only retain the fold in the shape given to it by the preceding rotary folding stage but may also further shape the material in preparat-ion for the succeeding rotary folding stage, so that the fold may be progressively changed in shape from one rotary stage to the next.

As the folding mechanism at each extremity of the bag is, or may be identical, it will be sufficient to describe the folding mechanism at one extremity.

' As may be seen more particularly from Figs. 1 and 2, the first seven rotary folding stages are effected by pairs of horizontal rolls, the next three rotary folding stages are efiected by sets of vertical rolls,- and the final rotary folding stage is effected by horizontal rolls. In all the stages the rolls are preferably so formed as to feed the bag blank forwardly from one set of rolls to the next.

The first pair of rolls 10 are primarily scoring rolls, as more particularly illustrated at stage A in Fig. 2a. Each of the rolls is provided with a grove 11 (Fig. 3) and a circumferential rib 12, the rib of one roll mating with the groove in the other roll. These mat-- ing ribs and grooves are spaced axially of the rolls by an amount equal to the length of that arm of the T, to be formed, which contains the reentrant fold, in other words, the distance between the points 13 and 14- in stage II. Hence the material of the blank is scored or creased by the action of the cooperating ribs and grooves at the two points at which the bends exist inrthe T shaped fold that is ultimately formed.

From rolls 10, in the form shown, the scored material passes between a pair of plates 15 which are spaced horizontally and slightly overlapped vertically so that their edges at the receiving end are in alignment with the mating ribs and grooves of the rolls 10. These plates may be parallel throughout their length so as to merely retain the form effected by the rolls 10, or they may be suitably shaped so as to slightly accentuate the scoring that has been effected by the rolls 10. As illustrated in Fig. 2, the plates 15 at their forward and rearward edges are curved in arcs of circles conforming with the rolls immediately preceding and following the same, so that the edges of the plates may be brought closely into adjacency with the periphery of the rolls, to the end that each point lengthwise of the fold is substantially always under the control and restraint of either a pair of rolls or a pair of plates.

Following the plates 15 a second pair of rolls 16 which bend the scored material into substantially the form illustrated at stage B in Fig.2a. From rolls 16 the blank passes in succession through pairs of rolls 17, 18, 19, 20 and 21 in which the material is progressivcly folded into substantially the forms shown at stages C, D, E, F and G in Fig. 2a, and in passing from one rotary folding stage to the next the folds are preferably subjected to the action of pairs of folding or tucking so that each pair of plates is so related that it receives and retains the material in the form delivered by the preceding roll. By

preference these plates are also so shaped as to accentuate and increase the shaping effect of the preceding rolls so as to prepare the fold for passage into the next succeeding pair of rolls.

From the rolls 21 the folded material, which has now nearly reached its T formation, preferably passes between a pair of suitably shaped plates 27, similar in character to the plates between succeeding pairs of rolls heretofore. described, but suitably formed to receive and retain the shape given to the fold by the pair of rolls 21 and also preferably shape it toward the form to be given the fold by the succeeding pair of rolls, and thence into cooperative relation with the first of threesucceeding stages of vertical rolls. As shown at stage H in Fig. 2a. the first set of vertical rolls 2S completes the T fold and compresses that arm of the T containing the reentrant fold, to force its component elements into close airtight engagement. From rolls 28 the folded materialpasses in succession to rolls 29 and 30 which progressively fold the two arms of the T toward the stem of the T, as illustrated at stages J and K in i Fig. Between rolls 28 and 29 and between rolls 29 and the. folded material is preferably subjected to pairs of plates 31 and 32 respectively, which are similar in character to the plates between succeeding pairs of rolls heretofore described but suitably formed to receive and retain the shape given to the fold by the preceding pair of rolls and also preferablv shape it toward the form to be given the fold by the succeeding pair of rolls. Rolls 30 preferably deliver the folded material to a pair of plates 33 similar in character to those heretofore described and which are preferably shaped to forward the folding of the arms of the T into engagement with the sides of the stem thereof, and these plates deliver the folded material to the final rolling stage illustrated at L in Fig. 2a and effected by a pair of horizontal rolls 3-1 as illustrated in Fig. 2. These last rolls compress and iron the folds tightly into airtight engagement. forcing the plies into a compact mass with the arms of the T folded into reenforcing relationship with the stem thereof. The folded material is now ready to receive the fastening means.

While it is preferred to employ between the succeeding pairs of rolls the pairs of plates heretofore described, which not only retain the material in the shape in which it is delivered by the preceding rolls, but also are preferably so formed as to shape the material toward the form to be given it by the succeeding rolls, it is to be expressly understood that it is within the contemplation of this invention, particularly when operating on material which by reason of its character or thickness is adapted to readily retain the form given to it by the rolls, to omit these intermediate plates and use only the succeeding pairs of rolls, which may be increased in number, if desired, so as to decrease the amount by which each succeeding pair of rolls changes the contour of the folds. So also, where the character or thickness of material makes it desirable, the number of rolling stages may be increased even when intermediate pairs of plates are employed and whether the plates are so shaped as to merely retain the form given the material by the preceding rolls or so'shaped as to progress the form from the preceding rolls toward that to be given it by the succeeding rolls. On the other hand, where the characteror thickness of material permits, the number of rolling sta ges may be decreased, or the plates may be designed to merely retain the shape given to the material by the preceding rolls, or under suitable conditions the intermediate plates may be omitted as well as the number of rotary folding stages decreased.

The rolls employed at the several rolling stages may be of any suitable construction and mounted and driven in any suitable way. As heretofore pointed out, the first seven rotary stages are preferably effected by pairs of horizontal rolls. As shown in Figs. 3 and 5, these rolls are not only provided with opposed coacting shaped surfaces by which the material of the blank is given the appropriate conformation for the particular stage in question, but said rolls are also provided with axially extending cylindrical extensions 40 projecting inwardly for sufficient engagement with the body of the blank to serve as feeding elements. As shown, these axial extensions 40 are knurled to provide suitable gripping surfaces, but if desired these cylindrical extensions 40 could be covered with or made of any suitable friction material for properly feeding the blank.

The several pairs of horizontal rolls are mounted in cooperative relationship in any suitable way. s shown in Fig. 5 which illustrates the rolls 20 of the sixth rotary folding stage, the lower roll of each pair is mountt'd' on a spindle 41 which is carried by the frame or a plate mounted thereon. Said roll is suitably retained on its spindle, as by a collar and set screw 42. The upper roll of each pair is mounted on a spindle 43, shown as carried by an L-shaped bracket 44, said roll being suitably retained on its spindle, as by a collar and set screw 45.

Bracket l4: is preferably mounted for vertical movement and resiliently urged toward the lower roll so that the rolls are maintained neaaeao in proper'cooperative relationship and yet the upper roll may give with respect to the lower roll to compensate for varying thicknesses of the material passing between the same. In the form shown, the lL-shaped bracket 44 is provided with flanges 16 which work in correspondingly shaped grooves formed in a re taining plate 48 suitably mounted on the frame. Suitably formed on or attached to' the frame member 2 is an overhanging lug or plate 49 which carries a cylindrical socket 50 which receives a coil spring 51 that bears on the horizontal element of the l..-shaped bracket 44: and thereby normally urges said bracket downwardly to hold the cooperating rolls in contact. Provision may be made for adjusting the tension of said spring if desired, and in the form shown a plunger 52 engages the end of the coil spring and is in turn engaged by a bolt 53 threaded into the end of the cylinder 50. To guide the movement of the bracket 44 and maintain rectilinear movement thereof, a bolt 54: may be passed through an aperture in the plate 49 and threaded into the horizontal member of the bracket 44, so that the bolt moves with the bracket and is guided by its engagement in the aperture of the plate 4-9. Each of the pairs of rolls 10, 16, 17, 18, 19, 20, 21 and 34- maybe mounted in the manner just described.

in the form shown, meshing pinions 55 and 56 are respectively formed on or suitably at tached to the rolls, and one of these rolls is driven in any suitable way, as in the manner hereinafter described.

The vertical rolls may also be of any suitable construction and mounting, and driven in any suitable way, but in view of the shape of the material upon which these rolls are acting the inner roll of each pair must be subdivided and spaced so as to permit passage of the body of the blank between the ends thereof. it. preferred construction is illustrated in 6. its here shown, the rolls of each stage are mounted on a'base plate 59 suitably secured to the frame and provided with a plurality of bracket elements 60, 61, 62, 63, and 6 1 which form bearings for the several elements to be described.

lifounted between the bracket elements 61 and 62 is the rear roll 65 which is preferably formed as a single roll having a circumferential groove midway of its length and knurled cylindrical or conical surfaces, depending on the stage, at either side of the groove. The spindle 66 of the roll 65 projects beyond the bracket elements 61 and 62 and has bearing engagement therein and in the bracket elements and 63. Suitably attached to the spindle 66, between the bracket elements 60 and 61 and between the bracket elements 62,

and 63, are pinions 67 and 68.

Pivotally mounted on the bracket elements 60 and 61 and on the bracket elements 62 and 63 are ti -shaped frame members 70 and 71 each of which carries one. of the two sections 72 and 73 of the forward rolls and a pinion, 74 and 75, for meshing with the pinion at the corresponding" end of the rear rolls 67 and 68. As the two frame members 70 and 71 and the parts carried thereby are of the same construction it is sufficient to describe one. Taking frame member 70, said frame includes a pair of horizontal arms 76 and 77, and rotatably mounted in said arms is the spindle 78 of the roll 72 which is located below the arm 77. Between the arms 76 and 77 said spindle carries the pinion 74 for meshin with the pinion 67. Projecting from the base plate 59 and extending loosely through an aperture in the end of the arm 76 is a pin 80 which carries at its outer end a coil spring 81 that bears at one end against the extremity of the arm 76 and at its opposite end against an adjustable washer and nut 82.

Each of the frame elements 70 and 71 are therefore normally urged toward the rear roll by a spring pressure which may be adjusted, so as to normally maintain the pinions 74: and 75 in mesh with the corresponding pinions 67 and 68 and the roll elements 72 and 73 in cooperative relation with the rear roll 65, but each of the forward rolls 72 and 73 may move independently of the other and relatively to the rear roll 65 so as to compensate for variations in the thickness of the material and in the thickness of one arm of the 'l' with respect to the other. The two forward rolls 72 and 73 are driven from the pinions 67 and- 68 on the rear roll spindle 66, which in turn is driven in any suitable way, as described more fully hereinafter. Each of the rolls 28, 29 and 30 are or may be of the construction just described.

In order to properly iron and compact the material being folded and prevent buckling or wrinkling of the material, with the consequent loss of an airtight seal, there should be a progressive increase in surface speed of the rolls from one end of the series of stages to the other. Experience has demonstrated that it is desirable to have the surface speed of the rolls increase at a rate corresponding to an increase in diameter of .01" per stage, but while this rate of increase in surface speed is at present preferred as the result of experience, the invention is not necessarily restricted to this rate of increase, as the rate of increase may be varied with the character of the material being operated upon.

Experience has also demonstrated that in order to prevent the line of fold being in clined to the edge of the material being folded, there should be a further increase in diameter of the rolls up to the place where the l" shape has been completedafter which the danger of the fold becoming inclined to the I edge of the material no longer exists. Accordingly, as shown in Fig. 2, there is a considerable increase in diameter of the rolls durrolls of a considerable increase in diameter over stage 3, stages 5 and 6 may increase over stage 4 at the .01 rate heretofore referred to,

and then there may be a considerable increase in diameter from stage 6 to stage 7. Vhere there is an increase in diameter in excess of the .01 heretofore referred to, the driving gears are so designed that the proper surface speed will be obtained notwithstanding the disproportionate increase in diameter.

In order to facilitate the folding operations during the first seven rotary folding stages particularly when many plies are to be folded, the rolls of each pair are preferably made in the form illustrated, as to the sixth stage, in Fig. 5, i. e. at the angles of the rolls where the bag material is being bent the coacting surfaces are provided with fins S3 and grooves 84 which produce a slipping ironing action at the line of bend.

In the ninth and tenth vertical rotary folding stages, where the arms of the T are being bent toward the stem of the T, the groove 85 in the rear solid roll and the peripheral edges 86 of the two forward rolls are preferably provided with knurled surfaces so that there is a strong'frictional grip of the rolls on the material of the bag at the lines where the bending is being eifected.

All the rolls are so designed as to produce square, as distinguished from sharp, folds at the lines of bending.

. lVhere bending or tucking plates are used between the succeeding roll stages to retain the shape of the fold as delivered by the preceding rolls or to further shape the fold toward the shape to be given it by the succeeding rolls, as heretofore described, the plates may be of any suitable construction and mounted in any suitable way, one preferred construction being illustrated in Fig. 4. As here shown, a pair of brackets 90 and 91 are mounted on the frame in any suitable way.

The bracket 90 has formed thereon orsuitably secured thereto a depending plate-like member 92, and the bracket 91 has formed thereon or suitably attached thereto a bifurcated end forming two fold engaging members 93 and 94. As heretofore explained, the spacing between the members 92 and 93 in a horizontal direction and the extent to which the member 92 projects into the space between the members 93 and 94 vary with the stage at which the plates are disposed, the surfaces 92,93 and 94 being so arranged that they at least retain the fold in the shape delivered by the preceding set of rolls.

The edges of the plates are preferably concavely curved so as to lie closely adjacent to the peripheries of the contiguous rolls, and

at the inlet to the space between these plates they are preferably flared. outwardly to a slight extent so that there will be no sharp corners to engage and tear the bag material. \Vhen the cooperating plates are to aid in the shaping of the folds, the members 92, 93 and 94 are so formed as to smoothly and gradually shape the fold from the inlet end to the outlet end thereof.

The character of plates illustrated in Fig. 4 is suitable for the plates after the first, second, third, fourth, fifth and sixth stages of rolling. After the seventh stage of rolling the fold has nearly reached a T formation and the cooperating plates after the seventh, eighth, ninth and tenth roll stages take the form illustrated in Fig. 2, wherein, considering plates 27 for example, the two plates 95 and 96 form a horizontal slot between their adjacent horizontal edges to receive the stem of the T and these plates cooperate with a rear platen to form recesses for receiving the two arms of the T, these last named recesses having such an angularity to the stem of the T as to hold the arms of the T in the form given them by the preceding rolls, and also preferably to bend the material gradually toward the form to be given it by the succeeding pair of rolls.

The final rotary folding stage, illustrated at L in Fig. 2a, is effected between two horizontal rolls 34 which function to iron and tightly compact the folds in their final shape with the two arms of the T compressed against the stem thereof in reinforcing relationship therewith.

Any suitable means may be employed for driving the rolls heretofore described. In the form shown, an electric motor 100 is mounted on the base plate or floor 4 and through pulley 101, belt 102 and pulley 103, drives a countershaft 104 which carries pinions 105. Meshing with pinions 105 as shown in Fig. 3 are pinions 106 on stub shafts 107 which also carry chain gears 108. From chain gears 108, chains 109 drive chain gears 110 on the spindles 41 on the lower rolls of the sixth rolling stages (see Fig. 5). The upper rolls of this stage are driven from the spindles of the lower rolls through the pinions 55 and 56. The fifth stage rolls are driven from the spindles of the lower rolls of the sixth stages by idler gears 111 mounted on the frame and meshing with the pinions 55 on the spindles of the lower rolls of the sixth and fifth stages. Similarly, the fourth stage rolls are driven from the lower spindles of fifth stage rolls by idler pinions between the pinions 55 of the two stages, and similarly the third stage rolls are driven from the fourth stage, the second stage rolls are driven from the third stage and the first stage rolls are driven from the second stage. In each of the stages the upper rolls are driven from the reeaeso spindles of the lower rolls through the meshing pinions and 56.

'1 he lower roll of the seventh stage is driven from the spindle of the lower roll of the sixth stage through three idler pinions mounted on the frame, and one of these idlers carries a beveled pinion 112 (Fig. 6) which meshes with a beveled pinion 113 on a vertical stub shaft 11.4 carried in a bracket 115. shaft-114 carries a chain gear 116 and through chain 117 drives a chain wheel 118 on a stub shaft 119 carried in the bracket element 63 and 64 on the base plate 59 of the eighth stage rolls. Stub shaft 119 carries a pinion 120 which meshes with a pinion 121 on the spindle 66 of the rear roll 65. Also mounted on the spindle (56 of the rear roll 65 is a chain wheel 122 which through chain 123 drives a chain wheel 124 on the stub shaft 78 of the ninth stage rolls, and similarly the tenth stage rolls are driven from the ninth stage 1011s through similar gearing.

The lower spindle 41 of the sixth stage rolls also carries a second chain gear 125 which through chain 126 3) drives a chain wheel 123 on the lower spindle of the eleventh stage rolls (Fig. 9), the upper roll of the eleventh stage being driven from the spindle of the lower roll by meshing pinions 55 and as heretofore described in conjunction with the first seven stages.

The further progress of the bag blank, after it leaves the eleventh stage rolls 34, brings the blank into cooperative relationship with the mechanism for fastening the folds together. As here again the mechanism is or may be duplicated on each side of the machine, where as illustrated the blank is to be closed at both extremities, it is sufficient to describe the mechanism at one side only of the machine.

Referring particularly to Fig. 9, the bag blank as it leaves the eleventh stage rolls is engaged andfed forwardly by feed rolls of any suitable character. As shown, there are three pairs of feed rolls 130, 131 and 132 shown cylindrical rollsknurled on their surfaces so as to grip and advance the bag.

tdaid feed rolls are driven in any suitable way. As shown, (see Fig. 9), the upper feed roll of each pair is driven by gearing carried by the frame and the lower roll of each pair is driven from the spindle of the upper feed roll. The spindle of the lower roll 34 of the eleventh stage carries a pinion 130 which meshes with a pinion 131 on the stub shaft 132. Stub shaft 132 carries a chain gear 133 which, through chain 134., drives the chain wheel 135 on the spindle 136 of the upper feed roll 130. T he spindle 136 also carries a pinion 131' which meshes with an idler 138 suitably mounted on the frame, and this idler meshes with a pinion 139 on the spindle of the upper feed roll 131. Similarly, the spindle of the upper feed roll 132 is driven Stub.

through idler 140 and pinion 141. Each of the spindles 142 of the lower feed rolls carries a pinion 143 in mesh with a pinion on the corresponding upper roll spindle, as illustrated.

T he spindles of the upper rolls are mounted in the frame of the machine, but the spindles of the lower roll of each pair are so mounted that the lower rolls may be separated from the upper rolls of each pair, to discontinue the feed of these rolls during the operation of the fastening mechanism. As shown, the spindles 142 of the lower rolls are mounted at their inner ends in a bar which may have vertical movement, the outer ends of said spindles being also suitably mounted to provide for the operation about to be described. Bar 150 has pivotally at tached thereto a pair of links 151 which are in turn pivotally connected at 152 to crank arms 153 pivotally mounted on the flange'154 of a plate suitably secured to the frame of the machine. The crank arms 153 are connected by a link 155 so that the bar 150, links 151 and link 153 constitute a parallelogram. The upper edge of plate 154 extends parallely to the bar 150 and when the feed rolls are in cooperative relationship the lower edge of the bar 150 is on the order of an eighth of an inch above the upper edge of the flange 154. The links 151 and crank arms 153 constitute a toggle mechanism, and when the toggles are broken at the joints 152 the bar 150 is lowered onto the upper edge of the flange 154, thereby moving the lower feed rolls out of feeding relation with the upper feed rolls.

As the bag is fed forwardly by the feed rolls heretofore described, the folds are retained in the position in which they are delivered from the final rolling stage of the rolls 34. To this end the folds are passed through a channel formed between upper and lower longitudinally extending fold-engaging guides 15'? and 158 suitably carried by the frame (see Figs. 2, 7, 9 and 13), and the upper guide may be so mounted as to exert a resilient pressure on the fold. Guide 158 carries the strip 159 at its forward edge, an upper surface of said strip being spaced from the under surface of guide 157 sufficiently to receive the body of the bag and the rectangular recess formed between and within the guides 157, 158 and the strip 159 being such as to retain the fold in the final form in which it leaves the rolls 34.

Means are provided whereby when the bag has been fed forwardly to such a position that its rear edge has suitably passed out of engagement with the rolls 34, the forward feed of rolls 130, 131 and 132 is discontinued, by separation of said rolls as heretofore de scribed, in order that the bag blank shall be temporarily brought to a state of rest and the action of the fastening mechanism initiated, the feeding mechanism associated with the fastening mechanism being also brought into action at the same time. As shown, the forward edge of the bag engages a trip mechanism at each side of the machine, and as here again the mechanism is or ally mounted on pin 172 is a pawl-like element 173 which carries a pin 174 projecting from both sides thereof. The head of pawl 173 also provides a shoulder 17 5. When the toggle mechanism heretofore described has its elements 151 and 153 in alignment, so that the bar 150 is holding the feed rolls in cooperative relationship, the trip finger 170 is in its upright position as shown in Fig. 8

ward crank arm 153. In this position the shoulder 175 is forwardly of said pin 176. The toggle mechanism isretained in this position by a latch 177 pivoted on the flange 154 at 178 and having a notch 179 which is adapted to engage the pin 17 6. Latch 177 carries a beveled lug 180 on its inner face for engaging the adjacent end of the pin 174:.

lVhen the forward edge of the bag engages the trip finger 170, the trip finger is moved in a clockwise direction around pivot 171 and the pawl 173 is moved to the right as viewed in Fig. 8. The end of pin 17 4 acts on beveled lug 180 to cam latch 177 upwardly so as to release pin 176, and immediately thereafter the shoulder 17 on latch 173 engages said pin 176 and moves it toward the right as viewed in Fig. 8. This breaks the toggle and permits the bar 150 to drop by gravity, or under the action of a suitable spring if desired, after 7 which pawl 173 is out of engagement with pin 176 and trip finger 170 may move until its free end is depressed below the blank. The feed rolls 1.30, 131 and 132 are thus disconnected from the bag and the bag is stopped in its forward position, holding the trip fingers 170 depressed sufficiently to permit the bag to pass thereover when the feed rolls are again brought into cooperative relation in the manner hereinafter described.

. The disconnection of the feed rolls in the manner heretofore described is also preferably used to bring into operation the fastening mechanism, this construction having the ,advantage that the fastening mechanism is out of operation until the bag is in the proper position to have the folds thereof secured together, and as the fastening mechanism comes into operation only when a bag is in proper position, there is no necessity for providing mechanism to insure that a bag shall be brought into fastening position at regularly timed intervals in order to cooperate with time-operated fastening mechanism.

Any suitable fastening mechanism may be employed, but in the form shown the fastening mechanism takes the form of a bank of stapling mechanisms of any suitable character and construction. As the present in vention does not require the use of any particular construction of stapling mechanism, the stapling mechanisms have been illustrated diagrammatically. Any suitable number of stapling mechanisms may be used, the mechanisms illustrated being of the general type shown in my Patent No. 1,653,051 heretofore identified so as to enable a number of these devices to be banked into a fairly short space lengthwise of the machine.

For purposes of exemplifying the present invention it is assumed that the blank is to be fastened at both extremities and that the bag H to be formed is of the type having a valve and the pawl 1.43 overlies a pm 176 pro ect- 111g inwardly from an extension on the rearopening at one corner. For closing this type of bag, in the form shown, six stapling mechanisms are mounted on that side of the machine which closes the end opposite the valve opening. and five stapling mechanisms are mounted on that side of the machine which includes the valve opening, the latter five being in transverse alignment with the first five stapling mechanisms on the opposite side, and the sixth stapling mechanism on the latter side operating on that corner of the bag which is opposite the valve opening in the other extremity of the bag.

The stapling mechanisms are brought into operation in any suitable way. In the form shown in Figs. to 12. a constantly rotating pulley 190 is driven in any suitable way, as by a belt from the countershaft 104, and normally rotates freely on a shaft 191 carried by the frame of the machine. Mounted on the hub of said pulley is a member having a cam groove 192 which starts from the surface of said member and increases in radius for a portion of its length, then continues at constant radius for a major portion of the circumference, and then decreases in radius, also decreasing in depth until it merges into the surface of said member. Secured to the stub shaft 191 is a clutch member 193 and a member 194 which carries or has suitably attached thereto a bevel gear 195. Mounted within a recess in said clutch member 193 and said member 194 is a clutch pin 196 having the form shown in Figs. 11 and 12, said member 196 being urged toward the left as viewed in Fig. 11 by a coil spring 197 housed in said recess. Said coil spring 197 moves clutch pin 196, when free to move, so as to project its end 198 into the path of a pin 199 carried by the pulley 190, so as to drive the shaft 191 and bevel pinion 195 from the pulley 190.

Pin 196 is normally retained in retracted position, however, by the engagement with an upstanding lug 200 thereon of the beveled if It nstance surface 201 on a latch element 202 pivotally mounted on rod 203. Latch 202 also carries a pin 204: which is normally urged to the left as viewed in Fig. 11 by a spring 205, and when free to move under the action of said spring, said pin 204 engages in the cam slot 192. Thereupon, cam groove 192 moves latch 202 radially outward so as to release the projection 200 on the clutch pin 196, permitting the latter to be moved by its spring 197 into the path of pin 199, whereupon the shaft 191 is driven from the pulley 190. During the major part of one revolution of the cam 192 the latch 202 is held in its radially outward position, but as the cam approaches the end of its revolution the latch 202 is moved radially inward into a position wherein the inclined surface 201 will engage the lug 200 and retract the pin 196, thereby stopping the shaft 191 at the end of one completerevolution. At the same time the decreasing depth of the cam groove 192 cams the pin 20% utwardly to its original position in which it is retained by'the mechanism next to be described.

Loosely pivoted on the rod 203 is a lever 200 having a fin 207 adapted to engage in a groove 208 in the pin 1. At its opposite extremity lever 206 carries a pin 209 which engages in a notch 210 in a rod 211 which extends downwardly exteriorly of the frame of the machine and is connected at its lower end to a lever 212 pivoted on the frame at 213 and projecting to the inner side of the frame where it carries, by means of a universal joint 21 1, an upstanding post 215 which engages the underside of the bar 150. "ll/ hen the bar 150 drops in the manner heretofore described, it thrusts the post 215 downwardly, and through the lever 212 thrusts the rod 211 upwardly, thereby swinging the lever 200 about its pivot 203 in an anticlockwise direction, withdrawing the fin 207 from the groove 208 and permitting the pin 20A to be moved by its spring 205 into the cam groove 1f, at the instant the pin 2041 is released the entrance to the cam groove is not opposite the pin, the end of the pin will ride on the face of the cam member until the entrance to the cam groove has come opposite the pin, after which the sequence of operation will occur in the manner heretofore described.

The shaft 191 is connected to the stapling mechanisms and drives the same to form and insert staples into the folds of the bag. In the machine illustrated, the connection between the shaft 191 and the stapling mechanisms is such as to edect three actuations of each stapling mechanism during one cycle of 'ation of the earn 192, all of the stapling mechanisms of both banks being operated simultaneously. Accordingly, mechanism is 'ovided for feeding the bag so as to step the forwardly three times to the end that each stapling mechanism will insert three engages at each forward corner a feeding I head 220 which is first deflected laterally to permit the bag to pass and then is moved inwardly to'engage the rear edge of the blank adjacent one corner thereof. Feeding mechanism of this character is provided at both extremities of the bag and is best illustrated in Fig. 9. The feeding head 220 has a feed ing face 221 at right angles to the length of the machine that is designed to engage the rear edge of the bag for feeding purposes. The opposite face of the feeding head 220 is beveled so that the forward edge of the bag may earn it out of its path. To this end the feeding head is carried by a lever 223 pivoted on a longitudinally extending rod 224 and having at its lower end a coil spring 225 which normally urges the feeding head into the path of the blank between the fold-engaging guides 157 and 158; Therefore, as soon as the bag has passed the feeding head,

the coil spring 225 moves the lever 223 around its pivot and snaps the feeding face 221 of the head 220 into engagement with the rear edge of the bag in the position at which the bag stops when the bars 150 are lowered in the manner heretofore described.

The feeding heads 220 are then given three intermittent forward movements. To this end, the rods 224 on which the levers 223 are pivoted are mounted to move lengthwise of the machine, and each of these rods car= ries a bracket 230 which is fixed to the rod and embraces the pivot of the lever 223 in the manner clearly illustrated in Figs. 7, 8 and 9. Each bracket 230 at its outer end carries a pin 231 which engages in the outer end of a lever 232 pivoted on the frame of the machine at 233. A coil spring 234 attached to each lever and the frame of the machine normally urges each lever 232 in an anticlockwise direction. The two levers 232 are connected intermediate their length by a trans versely extending rod 235 so that they are caused to move in unison. One of the levers 232 is provided with a crank arm 236 which carries a cam follower 237 for cooperation with a cam 238 clearly shown in Fig. 9. Cam

238 is provided with three dwells and three meshes with the bevel gear 195 heretofore described.

Transverse rod 235 also carries mechanism for restoring the feed rolls 130, 131 and 132 into cooperative relationship. As shown, each end of the rod 235 carries an arm 250 which at its forward end, as shown particularly in Fig. 8, has an elongated slot 251 and of the pin 174, by cooperation with the beveled surface of lug 252, cams the end of arm 250 upwardly in the same manner as the latch 17 7 is cammed upwardly by the action of the opposite end of pin 174:, so as to release the pin 176 when the toggle is to be broken. As the levers 232 and rod 235 are moved forwardly by the cam 238 the arm 250 is moved forwardly until the notch 251 drops over the pin 176. When the coil springs 234 restore the levers 232 to initial position at the end of one cycle of operation, the arms '250 are drawn to the left, as viewedin Fig. 8, pulling the pin 176 to the left and bringing the elements 151, 153 of the toggles into alignment, the latch 177 then engaging its notch 179 with pin 176 to lock the lower feed rolls in their upper position.

The stapling mechanisms are so timed with respect to the cam 238 that after the first forward movement of the levers 232, and

while the cam' follower 237 is cooperating with the succeeding dwell on cam 238, the

scribed.

stapling mechanisms are actuating to drive as many staples into the folds of the bag as there are stapling mechanisms. Thus in the form shown, five staples are driven into the lefthand edge of the bag as viewed in Fig. 14 and six staples are driven into the right-hand edge of the bag. These staples are designated X in Fig. 14. A second forward movement is then given the bag, and during the succeeding dwell a second series of staples designated Y in Fig. 14 is inserted into the folds. A third forward movement is then given to the bag and during the succeeding dwell the third series of staples, designated Z in Fig. 14, are inserted into the bag, after which the parts are restored to original position in the manner heretofore de- To provide for the insertion of the staples,

the upper fold-engaging guides 157 are provided with a series of apertures corresponding in number with the stapling mechanisms, and the lower fold-engaging-guide 158 is preferably provided op osite each aperture with a hard, and prefera ly removable, anvil which is engaged by and deflects inwardly the legs of the staple as it is driven through the folds of the bag.

When the toggle elements are brought into alignment in the manner heretofore described, thereby elevating the bar 150, the feed rolls 130, 131 and 132 are again brought into cooperative relation with the bag and aseaeso the bag is fed forwardly and out of the machine in its finished condition. If desired, additional feed rolls may be provided for carrying the bag out of themachine. In the form shown, a pair of feed rolls 260 are mounted in the frame of the machine in advance of the feed rolls 132, and also in advance of the position of the bag during the stapling operation. The upper feed roll spindle 261 carries a chain wheel 262 driven by a chain 263 from a chain wheel 264 on the spindle of the upper feed roll 132. The lower feed roll 260 is driven by means of meshing pinions 265 respectively carried by the upper roll spindle 261 and the lower roll spindle 266. Additional feed rolls similarly driven may be employed if desired. Also a feed belt for carrying the completed bags away from the machine may be employed as indicated at 268 in Fig. 2.

During the feed of the finished bag out of the machine by the feed rolls 130, 131, 132, together with such supplemental feed rolls 260 as may be employed, the trip fingers 170 are held depressed by the bag, but as soon as the bag has passed over them they are restored to upright position by light springs 270 (Fig. 8). Each pin 174 now rides over the tops of the lugs 180 and 252 and drops down at the forward edges thereof, so as to restore its cooperative relationship with said lugs for elevating the latch 177 and the restoring arm 250,'and breaking the toggle, when the next bag is fed forwardly into engagement with the trip fingers 170.

Operation From the foregoing detailed description, and the summaries of operation given from time to time, the operation of the machine as a whole is believed to be apparent, but it can 1 be briefly summarized as follows:

The bag blank is placed by hand or by machine on the platform 6 and engaged with the rolls 10 of the first stage. From'then on the operation is entirely automatic and requires no control of the operator. The bag is fed forwardly by the feeding portions of the rolls of the successive rotary folding stages and during the progress of the bag through the roll stages the extremities of the bag are gradually formed into T shape, and then the arms of the T are bent down onto the stem of the T and firinl rolled into a comact, airtight, reenforce quadraple-ply fold. t will be observed that'several of the roll stages are operating at the same time on the bag so that from the forward to the rear edge of the bag the material is being progressively and gradually folded into the final shape.

As the bag leaves the eleventh rotary folding stage it presses aside the feeding heads 220 and is engaged in succession by the feed rolls 130, 131, 132 until the bag is advanced forwardly to the position in which the staples .sition.

aeaaeeo are to be applied. During this time the fold is being kept in its completed and compact condition by the retaining fold-engaging guides 157 and 158 and the strip 159. As the bag reaches the position in which the staples are to be applied, its forward edge depresses the trip fingers 170 breaking the toggles 151 and 153 and simultaneously lowering the bars 150 to discontinue the feeding action of the rolls 130, 131, and 132. Simultaneously with this action the feed heads 220 move inwardly to engage the rear edge of the bag.

The depression of the bar 150 Withdraws the fin 207 from the groove 208 of the pin 204, permitting said pin to move into cooperation with the cam groove 192, whereupon the wedge surface 201 is removed from the lug 200 and the projecting end 198 of clutch pin 196 is moved into the path of clutch pin 199 so that shaft 191 is positively driven. Shaft 199 operates the cum 238 to cause the feed heads 220 to give the bag three short intermittent forward movements, with intermediate periods of dwell during each of which dwells the entire bank of stapling'meehanisms is actuated to drive staples into the folds.

At the end of the stapling operation the toggle mechanism is straightened to restore feeding engagement with the bag of the rolls 180, 131, 132 and the completed bag is fed out of the machine. llhe parts are now all restored to original position and remain so until the next bag is brought into stapling po- The stapling mechanisms are so timed that the bags may be fed into the machine in close succession and the staples will be inserted and the bag fed out of themachine as rapidly as the folded but unstapled bags are delivered from the final rotary folding stage rolls. lhe bag is advanced in a substantially continuous motion from its introduction into the machine until it is delivered therefrom, except for the .very brief pauses at the instants at which the staples are being inserted, the bag having a uniformly interrupted movement during the operation of fastening mechanisms, as distinguished from heretofore suggested procedures in which the bags are folded at ore or more stations and then moved bodily to successive stations in which the staples are applied.

lit will also be perceived that a method and machine have been provided whereby a strong, tight closure may be rapidly effected in relatively large bags, and in bags of rela tively stiff material, and at either one or both ends thereof, and the closure thereby efiected is of such strength as to minimize the likelihood of the bag being broken open by the weight of the contained material or by rough handling, while the closure is substantially airtight, because of the compactness of the folds and the closeness of the staples, so that sifting of the contained materialis prevented and the bag may be used for confining poisons and finely pulverized materials like flour, cement, plaster, etc.

It will further be perceived that the ma-' chine is one which may be operated at high speed and by comparatively unskilled labor, because it is entirely automatic in operation, requiring only the insertion of the blank at one end of the machineand even this may be performed by automatic feeding mechanismwhile the completed bag is automatically delivered from the opposite end of the machine Without any intervention of an operator. A substantially even fold is assured throughout the width of the blank, and the fold is maintained parallel to the edge of the blank.

The present invention enables the use of fastening mechanism which is set into operation only when a bag is in proper position to receive the fastening means, and thereby it is not necessary to assure that the bag blanks reach the fastening mechanism at properly timed intervals. The machine also includes improved folding mechanism, improved means for actuating and controlling the fastoning mechanism and improved mechanism for feeding thebag with relation to the fastening mechanism.

While the machine illustrated on the drawings has been described with. considerable particularity, it is to be expressly understood that the meehanical features of the invention are not restricted to a machine of the construction illustrated and described, as the invention is capable of receiving a variety of mechanical expressions, some of which Will now readily suggest themselves to those skilled in the art. While the machine is illustrated as folding and fastening both edges of a bag blank, the machine may be constructed to operate on only one edge, and the folding and fastening may be carried out on a filled bag as well as a bag blank. The machine may be of any suitable size to handle blanks or bags of any suitable size and thicknessand character of bag material, and the folding and fastening mechanism may be so arranged as to act on a bag or blank moving in a vertical or inclined plane as Well as in a horizontal plane. While the invention has been illustrated by reference to a \bag formed of material having five plies, making ten thicknesses to be folded, the method and machine are applicable to the closing of bags of which is formed of a single thickness of suitable material. Certain features of the invention may be used without other features thereof extendin at an angle to the body of the bag, progressively folding the sections of said reentrant fold into engagement with both sides of the body, and uniting the folds in said last-named relationship.

2. The method of closing' bags which includes progressively folding the bag material into substantially a T shape, progressively folding the arms of the T into engagement with the body of the bag at both sides thereof, and uniting the folds in said lastnamed relationship.

3. The method of closing bags which includes progressively bending the .bag mater'zal transversely to its edge and also along its edge to produce a reentrant fold, progressively bending the reentrant fold onto the opposite sides of the body of the bag, and securing the folds together in said last-named relation.

4. The method of closing bags which includes forming progressively, both transversely and longitudinally of its edge, a T- shaped fdld in the bag material, bending progressively, both transversely and longitudinally, the two arms of the T into reenforcing relationship with the stem thereof, and securing the folds together in said lastnamed relation.

5. The method of closing bags which includes progressively forming areentrant fold in the bag material with the sections thereof extending at an angle to the body of the bag, progressively folding the sections of said reentrant fold into engagement with both sides of the body, and inserting a series of closely spaced staples through said folds in said last-named relationship.

6. The method of closing bags which includes progressively folding the bag material into substantially aT shape, progressive- 1y folding the arms of the T into engagement with the body of the bag at both sides thereof, and inserting a series of closely spaced staples thrbugh said folds in said last-named relationship.

7. Themethod of closing bags which includes progressively bending the bag material, transversely of its edge and also along its edge, to produce a reentrant fold, progressively bending the reentrant fold onto the opposite sides of the body of the bag, and

inserting a series of closely spaced staples through said folds in said last-named relat-ion.

8. The method of closing bags which includes forming progressively, both transversely and longitudinally of its edge, a T- shaped fold in the bag material, bending progressively, both transversely and longitudinally, the two arms of the T into reenforcing relationship with the stem thereof, and inserting a series of closely spaced staples through said folds. in said last-named relation.

9. The method of closing bags which includes progressively forming a reentrant fold in the bag material with the sections thereof extending at an angle to the body of the bag, progressively folding the sections of said reentrant fold into engagement with both sides of the body, advancing said fold in a step-by-step motion, and inserting a plurality of fastening means through said fold during the intervals between each step-bystep motion.

10f The method of closing bags which includes progressively folding the bag material into substantially a T shape, progressive-' ly folding the arms of the T into engagement with the body of the bag at both sides thereof,

advancing said folds in a step-by-step motion, and inserting a plurality of fastening means through said folds during the intervals btween each step-by-step motion.

11. The method of closing bags which includes progressively bending the bag material transversely to its edge and also along its edge to produce a reentrant fold, progressi vely bending the reentrant fold onto the opposite sides of the body of the bag, advancing the resulting folds in a vstep-by-step motion, and inserting a plurality-of fastening means through said folds during the intervals between each step-by-step motion.

12. The method of closing bags which includes forming progressively, both transversely and longitudinally of its edge, a T"- shaped fold in the bag material, bending progressively, both transversely and longitudinally the two arms of the T into reenforcing relationship with the stem thereof, advancing the resulting folds in a step-by-step motion, and inserting a plurality of fastening means through said folds during the intervals between each step-by-step motion.

13. The method of closing bags whichincludes successively subjecting the bag mateal to a series of rotary folding elements which progressively form a reentrant fold in the material with the sections thereof extending at an angle to the body and then fold the sections of said reentrant fold intoengagement withboth sides of said body, and uniting said folds in said last-named relation.

14. The method of closing bags which includes successively subjecting the bag mate- QTE rsaaeeo rial to a plurality of simultaneously acting rotary folding elements, which progressively bend the blank into a reentrant fold and then bend the arms of the fold into reenforcingrelationship with the body of the bag, and securing said folds together in said last-named relationship.

15. The method of closing bags which includes successively subjecting the bag material to a series of rotary folding elements which progressively form a reentrant fold in the material with the sections thereof extendin g at an angle to the body and then fold the sections of said reentrant fold into engagement with both sides of said body, subjecting the bag between rotary folding stages to the action of stationary folding elements, and uniting the folds upon delivery from the final folding stage.

16. The method of closing bags which includes successively subjecting the bag material to a plurality of simultanegusly-acting rotary folding elements which progressively bend the bag material into a reentrant fold and then bend the arms of the fold into reenforcing relationship with the'body of the bag, subjecting the bag between rotary folding stages to the action of stationary elements which gradually advance the fold, and securing said folds together immediately after delivery from the final folding stage.

17. The method of closing bags which includes successively subjecting the bag material to a series of rotary folding elements which progressively form a reentrant fold in the material with the sections thereof extending at an angle to the body and then fold the sections of said reentrant fold into engagement with both sides of said body, intermit tently advancing the completed fold, and inserting fastening elements through said folds during the intervals between advances.

18. The method of closing bags which includes successively subjecting the bag material to a plurality of simultaneously-acting rotary folding elements which progresively bend the bag material into a reentrant fold and then bend the arms of the fold into reenforcing relationship with the body of the bag. intermittently advancing the completed fold, and inserting a plurality of fastening elements through said folds during the inter vals between each advance.

it). The method of closing bags which includes successively subjecting the bag material to a series of rotary folding elements which progressively form a reentrant fold in the material with the sections thereof extending at an angle to the body and then fold the sections of said rcentrant fold into engagenientwith both sides of said body, subjecting step-by-step motion, and inserting fastening elements through said folds during the intervals between advances.

20. The method of closing bags which includes successively subjecting the bag material to a plurality of simultaneously-acting rotary folding elements which progressively bend the bag material into a reentrant fold and then bend the arms of the fold into reenforcing relationship with the body of the bag, subjecting the bag between rotary folding stages to the action of stationary elements which gradually advance the fold, intermittently advancing the completed fold in a step by-step motion and inserting a plurality of fastening elements through said folds during the intervals between advances.

21. The method of closing bags which includes forming a reentrant fold and then bending the arms of the fold into reenforcing relationship with the body thereof by rotary folding elements which progressively increase in surface speed to exert a stretching and ironing action on the bag material, and then uniting said folds.

22. The method of closing bags which includes progressively forming a reentrant fold between rotary folding elements which increase in diameter, progressively folding the arms of the fold into reenforcing relationship with the body thereof, and uniting the folds in said last named relationship.

23. The method of closing bags which includes progressively forming a T-shaped fold in the bag material between rotary folding elements which stretchand iron the material, progressively bendin the arms of the T into reenforcing relationship with the stem thereof between the rotary folding elements which iron and compress the plies of the fold, and uirl iting the folds in said last named relations s 1p.

24. The method of closing bags which includes progressively forming a l -shaped fold in the blank between rotary folding elements which stretch and iron the material, progressively bending the arms of the T into reenforcing relationship with the stem thereof between rotary folding elements which iron and compress the plies of the fold, intermittently advancing the completed fold, and during the intervals between advances, inserting a plurality of fastening means through said folds.

25. In a machine for closing bags, a frame, a series of rotary folding elements arranged lengthwise of said frame and having surfaces shaped to progressively bend the bag mate rial into a reentrant fold and then bend the arms of the fold into contact with the body thereof, means for driving said rotary folding elements, and means for uniting the completed fold upon delivery from said rotary folding elements.

26. Tu a machine for closing bags, a frame,

will 

